<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./vue.js"></script>
</head>

<body>
    <div id="app">
        {{full}}
        <div>{{msg}}</div>
        <input type="button" @click="change" value="按钮">
    </div>
    <script>
        new Vue({
            el: "#app",
            data: {
                first: "你",
                last: "好",
                msg: "hello world"
            },
            computed: {
                full() {
                    console.log("计算一次")
                    return this.first + this.last
                }
            },
            methods: {
                change() {
                    setTimeout(() => {
                        this.msg = "我要改变"
                    }, 2000)
                }
            },
            mounted() {
                // change()
            },
        })
    </script>
</body>

</html>